German vehiclesAFV deliveries to Bulgaria up to December 31st 1943: Thirteen SdKfz. 222, 7 SdKfz. 223, fourty six PzKpfw. IV Ausf. G, ten PzKpfw. 38(t), twenty five StuG III Ausf. G. The StuGs were designated SO-75 by the Bulgarians. In February 1944, Germany supplied another nineteen Hotchkiss H-39 and six Somua S-35.

Bulgaria joined the war on the side of Germany in March 1941 by signing the Tripartite Pact. Bulgaria also allowed German troops to go through its borders to Greece. It also participated in the occupation of Macedonia. Bulgaria also sent troops to Yugoslavia to fight against partisans to keep the Belgrade to Greece roads open. The Bulgarian's started the war with the 14 Italian CV 33 tankettes acquired in 1934, 8 Vickers 6-ton tanks purchased in 1938, and 36 PzKpfw 35(t)s in February 1940. In June 1941 the 1st Armored Brigade was formed which was made up of the 1st Tank Regiment and 1st Mechanized Infantry Regiment. The tank regiment had a reconnaissance company of the CV 33 tankettes. The 2 tank battalions were made up of the PzKpfw 35(t)s and Vickers 6-ton in one, and 40 French R-35s donated by the Germans. The regiment never saw much action. In July 1943, the Germans updated the regiment with 46 PzKpfw IVs, 10 PzKpfw IIIs, 25 StuG IIIs, and SdKfz 222, 223s. On September 9, 1944, Bulgaria switched sides, after the Communist Fatherland Front seized power. The 1st Armored Brigade took part in the fighting in Hungary during 1945.